The F-flat half-diminished seventh chord (abbreviated "Fbm7(b5) chord") is a four-note chord consisting of the notes F♭, A♭♭, C♭♭, and E♭♭. The chord is formed by lowering the fifth of a F-flat minor seventh chord a half step.
F-flat half-diminished seventh chord
F-flat half-diminished chord F-flat minor seventh flat five chord
F♭ A♭♭ C♭♭ E♭♭
1 ♭3 ♭5 ♭7
F♭ø F♭ø7 F♭m7b5 F♭–7(b5) F♭mi7(b5) F♭min7(b5)
Tetrad (four-note chord)